Method of and means for photographing a reproduction original consisting of cards in a scale-like arrangement



Oct. 10, 1961 METHOD OF AND MEAN CONSISTING A SCALE-LIKE Filed larch 31, 1958 I JO/M/Y HEMP/K 15mm INVENTOR.

v- "mint Unite S ate Patent Qffice Patented Oct. 10, 1961 Filed Mar- 31, 1958, Ser. No. 725,292 1 Claim. (CI. 88-24) In the production of periodically appearing books and publications, such as directories, telephone books, and catalogues, it is known to use reproduction originals, which e.g. with a view to a change in the text of subsequent editions, consist of text elements on separate cards. The reproduction originals are formed by arranging the cards scale-like in rows, see my co-pending US. patent application Ser. No. 653,933, so that the text elements will form lines in a column or page of the printed matter, and are then transferred by photographing to a copying pattern, which appears as a photographic negative, and whose text picture is again transferred to a printing plate, with which the printing proceeds by usual methods.

When photographing such a reproduction original consisting of cards in a scale-like arrangement, the difliculty is encountered that shadows are produced at the edges of the cards, when the original is illuminated, as the lighting must be intense with a view to the speed ofjoperation,

said shadows appearing on the negative as dark linesbetween the text elements.

The present invention has for its object the remedying of this inconvenience, i.e. to avoid such dark lines on the negative.

According to this invention a fluorescent card material is used, which is partly illuminated by light falling, substantially at right angles, onto the card surface and evenly distributed thereover and partly by light falling obliquely from one side towards the cards edges. It has proved expedient that the light falling obliquely is substantially ultra-violet.

. The said method and a corresponding apparatus will now be explained in more detail, reference being had to the drawing, wherein FIG. 1 shows schematically an apparatus for photographing a reproduction original,

FIG. 2 is a horizontal cross section on a larger scale of the reproduction original of FIG. 1, showing the scalelike arrangement of the cards, and

FIG. 3 shows the cross section of FIG. 2 on a still larger scale, illustrating the lighting conditions at the edge of a card.

' overlapping each other to present free edges 24 all facing the same direction as shown most clearly, in FIG. 2. In

FIG. 1 the cards are shown arranged in three rows. 7 The cards 12 are situated on a support formed as a plate 14 and may e.g. be held in abutment against the said plate by means of a superimposed plate of glass, not shown. A photographic camera 16 serves to photograph the reproduction original 10, the optical axis of said camera substantially coinciding with a central line 18 at right angles to the original 10. During photographing, the original 10 is frontally illuminated by a number of light sources shown as electric lamps 20, which are suitably regularly distributed in a plane 22, which is perpendicular to the line 18 and is positioned in the proximity of the photographic camera 16, if desired behind the said camera.

I When the cards 12 are arranged scale-like, as mentioned heretofore, i.e. so that a portion not each card, on which a text element is provided, projects, all the cards will have a free edge 24 facing the same direction, i.e. to/the leftin'FIGJ. As aresult a'shadow will be formed at said edges in the form of a narrow stripe b. The shadthe front face of the subsequent card, whereas 24 is the I free edge of the first-mentioned card. The origin of this formation of shadows is that the light from the lamps 20, FIG. 1, strikes any point of the photographed surface in several different directions, of which the directions with the maximum inclination to the normal are indicated in dotted lines 32 in FIG. 3.

It might be assumed that these shadows could be avoided by a separate illumination of the reproduction original from the left side, whereby rays of light towards the card edges 24 would be produced almost at right angles thereto, as is suggested by a dotted line 34 in FIG. 3. In practice, such an illumination has proved to be inadequate, because the card edges situated nearest to the source of light will be considerably more intensely illuminated than those which are farthest away, so that it is impossible to produce a negative, wherein theshadow stripes are removed from the whole of the photographed surface.

The desired result, however, can be achieved when in addition a fluorescent card material is used, a marked fluorescence being thereby produced in the area of the card edges. Independently of the variation of the illumination intensity transversely of the reproduction original the said fluorescence has the effect that the formation of shadows disappears, at any rate from the picture'on the photographic negative. This is presumed to be due to a saturation phenomenon.

The aforesaid oblique illumination of the original 10 may be produced by a number of light sources, e.g. electric lamps 36, FIG. 1, which are placed laterally to the axis of the camera 16 and preferably in a trough-shaped box 38, whose opening faces the original.

All the lamps 20 and 36 used should emit strongly actinic light.

The card material used must be fluorescent all through, as the decisive factor is the fluorescence at the edges produced by cutting out the cards. Card material of this kind is known and produced, e.g. in order to obtain a surface, which appears particularly white. The fluoreseence substance is therefore named optical whiteness agent. A known substance used for this purpose is named Blaneophor.

The lamps 36 for the oblique illumination of the original 10 should be selected with a view to obtaining the desired uniform fluorescence. A useful type of lamp is a highpressure mercury-vapour lamp named Philips I-IPR eonsistingof a small discharge tube of quartz enveloped in an outer bulb of hard glass. Thislamp emits a large quantity of actinic radiation and its spectrum has a marked line in the ultra-violet region.

Having thus fully described my invention I claim as new and desire to secure by Letters Patent:

A method for photographing a plurality of cards carrying information thereon which are made of fluorescent material, comprising the steps of mounting said cards in rows on a support member in overlapping relationship such that a marginal portion of each card is exposed, directing light in a direct manner onto the exposed portions of said overlapping cards froma plurality of light sources disposed in a plane spaced from and parallel to said support member, projecting an ultraviolet light onto the free edges of said cards at an oblique angle thereto to fluoresce the free edges of said cards thereby avoiding casting of any shadows by the free edges of said cards onto cards overlapped by the exposed portions, and photographing the rows of overlapping cards illuminated by said directed and projected light.

References Cited in the file of this patent UNITED STATES PATENTS Ballard "Jail. 12, 1932 

